how to make a thread to a force thread...it means a thread want to see to all users before they browse the forum/......when the user once goto the site....then a notice want to see ...like ...the administrator want you to view a thread...clik here to the thread....

Do you mean, like mine has? Check mine - those two threads have NOT been blocked to ALL - so they pop up on entrance - however to access the rest of my site, the people need to register. You do that at Configuration in Admin mode. Click on the yellow checkmark red X symbol, and modify - when you see your site in Admin mode.